Printed circuit board axial flux machine for steer-by-wire handwheel actuator

Abstract

An axial flux machine (AFM) includes: a rotor assembly configured to rotate about an axis. The rotor assembly includes a first rotor core and second rotor core. Each of the first rotor core and the second rotor core have a plurality of permanent magnets attached thereto, and each of the first rotor core and the second rotor core are spaced apart and parallel to one another and perpendicular to the axis. The AFM also includes a stator assembly having a PCB located between the first rotor core and the second rotor core and parallel thereto. The PCB defines a stator winding configured to generate a magnetic flux in an axial direction through each of the first rotor core and the second rotor core to cause the AFM to generate a torque. A steer-by-wire system includes a handwheel actuator including the AFM coupled to apply a torque to a steering wheel.

What is claimed is: 
     
         1 . An axial flux machine (AFM) comprising:
 a rotor assembly configured to rotate about an axis and including a first rotor core and second rotor core, with each of the first rotor core and the second rotor core having a plurality of permanent magnets attached thereto, and with each of the first rotor core and the second rotor core spaced apart and parallel to one another and perpendicular to the axis; and   a stator assembly including at least one PCB located between the first rotor core and the second rotor core and parallel thereto,   wherein the at least one PCB defines a stator winding configured to generate a magnetic flux in an axial direction through each of the first rotor core and the second rotor core to cause the AFM to generate a torque.   
     
     
         2 . The AFM of  claim 1 , further comprising a motor shaft extending along the axis, wherein each of the first rotor core and the second rotor core is attached to the motor shaft to rotate therewith, and wherein each of the first rotor core and the second rotor core is disposed circumferentially about the motor shaft. 
     
     
         3 . The AFM of  claim 1 , wherein the at least one PCB includes a first PCB and a second PCB each extending parallel to one another and each located between the first rotor core and the second rotor core and parallel thereto. 
     
     
         4 . The AFM of  claim 1 , wherein the stator winding includes a first set of active windings and a second set of active windings independent of the first set of active windings, with either of the first set of active windings or the second set of active windings being operable to generate the magnetic flux and to cause the rotor assembly to generate a torque. 
     
     
         5 . The AFM of  claim 4 , wherein the at least one PCB includes a first PCB and a second PCB each extending parallel to one another and each located between the first rotor core and the second rotor core and parallel thereto; and
 wherein the first PCB defines the first set of active windings and the second PCB defines the second set of active windings.   
     
     
         6 . The AFM of  claim 1 , further including:
 a second rotor assembly configured to rotate about the axis and including a third rotor core and fourth rotor core, with each of the third rotor core and the fourth rotor core having a plurality of permanent magnets attached thereto, and with each of the third rotor core and fourth rotor core spaced apart and parallel to one another and perpendicular to the axis; and   a second stator assembly including at least one second PCB located between the third rotor core and fourth rotor core and parallel thereto,   wherein the at least one second PCB defines a second stator winding configured to generate a magnetic flux in an axial direction through each of the third rotor core and fourth rotor core to cause the AFM to generate a torque.   
     
     
         7 . The AFM of  claim 1 , wherein the stator winding is one of a plurality of phase windings, and wherein the at least one PCB defines each of the plurality of phase windings. 
     
     
         8 . The AFM of  claim 1 , wherein the at least one PCB further includes a passive damping winding having one or more short circuited configurations to produce a braking torque. 
     
     
         9 . The AFM of  claim 8 , wherein the at least one PCB further includes a resistance connected to the passive damping winding. 
     
     
         10 . The AFM of  claim 8 , wherein the at least one PCB includes: an active PCB defining the stator winding configured to generate the magnetic flux; and a passive damping PCB independent of the active PCB and defining the passive damping winding. 
     
     
         11 . The AFM of  claim 8 , wherein the stator winding includes a first set of active windings and a second set of active windings independent of the first set of active windings, with either of the first set of active windings or the second set of active windings being operable to generate the magnetic flux and to cause the rotor assembly to generate a torque,
 wherein the at least one PCB includes a first PCB and a second PCB each extending parallel to one another and each located between the first rotor core and the second rotor core and parallel thereto, wherein the first PCB defines the first set of active windings and the second PCB defines the second set of active windings, and   wherein the AFM further includes a passive damping PCB defining the passive damping winding, the passive damping PCB disposed adjacent and parallel to each of first PCB and the second PCB.   
     
     
         12 . The AFM of  claim 1 , further comprising a hybrid damping winding with a switch configured to selectively conduct current through the hybrid damping winding to cause the hybrid damping winding to generate a braking torque. 
     
     
         13 . The AFM of  claim 12 , further comprising a switch driver configured to control operation of the switch, and wherein the hybrid damping winding, the switch, and the switch driver are each disposed within or upon the at least one PCB. 
     
     
         14 . The AFM of  claim 1 , further comprising a plurality of hybrid damping windings and a plurality of switches, wherein each of the switches is configured to selectively conduct current through a corresponding one or more windings of the plurality of hybrid damping windings, and
 wherein varying a configuration of the plurality of switches to conduct the current through the corresponding one or more windings causes the AFM to produce a varying amount of braking torque.   
     
     
         15 . The AFM of  claim 14 , wherein the plurality of hybrid damping windings and the plurality of switches are each disposed within or upon the at least one PCB. 
     
     
         16 . A steer-by-wire system for a vehicle, comprising:
 a handwheel actuator coupled to apply a torque to a steering wheel;   the handwheel actuator including an axial flux machine (AFM) including:
 a rotor assembly configured to rotate about an axis and including a first rotor core and second rotor core, with each of the first rotor core and the second rotor core having a plurality of permanent magnets attached thereto, and with each of the first rotor core and the second rotor core spaced apart and parallel to one another and perpendicular to the axis; and 
 a stator assembly including at least one PCB located between the first rotor core and the second rotor core and parallel thereto, 
 wherein the at least one PCB defines a stator winding configured to generate a magnetic flux in an axial direction through each of the first rotor core and the second rotor core to cause the AFM to generate a torque. 
   
     
     
         17 . The steer-by-wire system of  claim 16 , wherein the at least one PCB includes a first PCB and a second PCB each extending parallel to one another and each located between the first rotor core and the second rotor core and parallel thereto. 
     
     
         18 . The steer-by-wire system of  claim 16 , wherein the stator winding includes a first set of active windings and a second set of active windings independent of the first set of active windings, with either of the first set of active windings or the second set of active windings being operable to generate the magnetic flux and to cause the rotor assembly to generate a torque. 
     
     
         19 . The steer-by-wire system of  claim 16 , wherein the at least one PCB further includes a passive damping winding having one or more short circuited configurations to produce a braking torque. 
     
     
         20 . The steer-by-wire system of  claim 19 , wherein the at least one PCB further includes a resistance connected to the passive damping winding.